Regional characteristics of 5--10 m scale carbonate cycles of Late Mississippian Greenbrier depositional sequences, West Virginia; Comparison of field and modeling results
- Virginia Polytechnic Institute, Blacksburg, VA (United States). Dept. of Geological Sciences
The Late Mississippian Greenbrier ramp carbonates contain depositional sequences (each up to tens of meters thick) which consists of a few transgressive shaly/muddy carbonates that shallow up into high energy skeletal/oolitic grainstones and associated shoreline facies and red beds. Sequence boundaries are characterized by erosional unconformities, caliches, breccias, channeling, and lowstand clastics. Superimposed on the larger scale third order cyclicity are high frequency, 5--10 m scale carbonate dominated cycles (parasequences), possibly of 100 to 400 KY duration each. Updip, few cycles are developed. These consist of grainstone-dominated facies with sharp/erosional tops, locally developed eolianites and caliches (especially where associated with a sequence boundary). Tidal flat facies are relatively rare and thin. In the much thicker downdip sections, more carbonate cycles are developed. Cycles are dominated by skeletal packstone grading up into skeletal/oolitic grainstone, and some thick (up to 8 m) tidal flat laminated dolomites. The oolites are sheets to channeled bodies that locally prograde out over local bioherms. Oolites are rare in the furthest downdip sections on the ramp. Cycle boundaries rarely have caliches, but erosional and microkarstic surfaces are common. Comparison of the observed sections with computer generated synthetic cross sections suggests that the cycles were developed under moderate amplitude (tens of meters) high frequency Milankovitch eustatic sea level fluctuations dominated by 100--400 KY periods. These likely mark the onset of the Late Carboniferous glaciation in Gondwana. The modeling closely simulates limited updip cycle development, and abundant cycle development downdip, along with locally well developed lowstand tidal flats.
- OSTI ID:
- 5588428
- Report Number(s):
- CONF-921058--
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Journal Name: Geological Society of America, Abstracts with Programs; (United States) Vol. 24:7; ISSN GAAPBC; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
Similar Records
High-resolution sequence stratigraphy of Late Mississippian carbonates in the Appalachian basin, implications for compartmentalization of reservoir facies
High-resolution sequence stratigraphy of Late Mississippian carbonates in the Appalachian basin, implications for compartmentalization of reservoir facies
Related Subjects
580000* -- Geosciences
CARBONATE ROCKS
CARBONIFEROUS PERIOD
COMPUTERIZED SIMULATION
DEPOSITION
DEVELOPED COUNTRIES
FLUCTUATIONS
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
LEVELS
NORTH AMERICA
PALEOCLIMATOLOGY
PALEONTOLOGY
PALEOZOIC ERA
ROCKS
SEA LEVEL
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
SIMULATION
STRATIGRAPHY
USA
VARIATIONS
WEST VIRGINIA